called & didn't leave msg

called my cell phone and did not leave a message
gives a message of this phone is no longer in service if called back

My caller ID says "WATERTOWN SD" - that is the location from which the call was made. I called it back and the msg says the # is no longer in service; However, the msg didnt sound like a standard phone company message. It sounded fishy to me.

This is a land line #..They keek calling me also ..You can block the # and they wont be able to call ..That is what I did!!